The present invention relates to linear motors of the type whose armature field is established by permanent magnets. More particularly, the invention relates to linear motors of the type including parallel ferro-magnetic bars connected to a magnetic system, with a coil arrangement mounted for movement along the length of the two bars, wherein the coil arrangement is energized by current and intersecting the magnetic field lines emanating from the bars.
The magnetization direction of the permanent magnets employed in such linear motors is perpendicular to the direction of armature travel and the magnetic polarity of successively positioned permanent magnets alternates.
Such linear motors may be employed as drive mechanisms for peripheral equipment in data processing applications.
The known linear motor is disclosed for example, in the U.S. Pat. No. 4,151,447. This motor comprises two parallel guide bars formed as a U-shaped profile with two elongated legs. At least two flat armature coils which are located one after the other in the direction of linear armature travel are provided. The broad faces of the coils are parallel to the general plane in which they move and their axles of windings are perpendicular to the direction of movement. In this construction a relatively great part of the energized coil participates electro-magnetically in the generation of motive force. However, with this construction the ends of the coils do not actually participate in the motive-force generation to advance the armature since they are located in the region where the coil conductors are moved in the direction of the movement of the coil arrangement. In this respect, it has to be considered that from the total length measured in the direction of movement of the coil arrangement that part which corresponds to the interior of the coils does not contribute anything to the motiveforce generation. To avoid this, an additional number of coils may be provided in the motor which may be placed within the interior of the coils, however this may complicate the armature-coils performance.